<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <link rel="stylesheet" type="text/css" href="../css/demo03.css">
</head>
<body>
<!--

  需求：让第二个和三个div的字体颜色变为绿色并设置大小为100px
-->
  <div>div1</div>
  <div class="myDiv">div2</div>
  <div class="myDiv">div3</div>
</body>
</html>